Where does the power come from on overcast and windless days?
Renewables definitely have their place, but they are nowhere near being able to replace the continuous production of FF and nuclear plants. Moreover, the grids were neither designed nor built to deliver power from massively distributed, massively variable sources.
There's a third problem too, which ecologically-minded people seem to overlook: renewables are only "renewable" if you consider the real estate they occupy to be infinite.
Again, there is an important place for these technologies, but it is not the case that we simply should have built more.
Power comes a) from another place in the European grid where it's sunny or windy, and/or b) storage. a) works decently well today, b) has room for improvement, but demand for storage is low, since we don't have a lot of surplus energy that we could put into storage. Right now it's pretty much always easier to turn down the fossil fuel plants when renewables are generating a lot, so that's what we do.
Medium/long term we can solve this with storage and load shifting. For the time being it still comes from fossil fuels and nuclear as you say. But using renewables when sun and wind are available would still dramatically reduce are fossil fuel consumption, which would in turn dramatically reduce costs.
Renewables definitely have their place, but they are nowhere near being able to replace the continuous production of FF and nuclear plants. Moreover, the grids were neither designed nor built to deliver power from massively distributed, massively variable sources.
There's a third problem too, which ecologically-minded people seem to overlook: renewables are only "renewable" if you consider the real estate they occupy to be infinite.
Again, there is an important place for these technologies, but it is not the case that we simply should have built more.